Temozolomide-Induced RNA Interactome Uncovers Novel LncRNA Regulatory Loops in Glioblastoma.

Resistance to chemotherapy by temozolomide (TMZ) is a major cause of glioblastoma (GBM) recurrence. So far, attempts to characterize factors that contribute to TMZ sensitivity have largely focused on protein-coding genes, and failed to provide effective therapeutic targets. Long noncoding RNAs (lncRNAs) are essential regulators of epigenetic-driven cell diversification, yet, their contribution to the transcriptional response to drugs is less understood. Here, we performed RNA-seq and small RNA-seq to provide a comprehensive map of transcriptome regulation upon TMZ in patient-derived GBM stem-like cells displaying different drug sensitivity. In a search for regulatory mechanisms, we integrated thousands of molecular associations stored in public databases to generate a background "RNA interactome". Our systems-level analysis uncovered a coordinated program of TMZ response reflected by regulatory circuits that involve transcription factors, mRNAs, miRNAs, and lncRNAs. We discovered 22 lncRNAs involved in regulatory loops and/or with functional relevance in drug response and prognostic value in gliomas. Thus, the investigation of TMZ-induced gene networks highlights novel RNA-based predictors of chemosensitivity in GBM. The computational modeling used to identify regulatory circuits underlying drug response and prioritizing gene candidates for functional validation is applicable to other datasets.

Long non-coding RNAs as novel therapeutic targets in cancer.

Thanks to impressive technology advancements, pervasive expression of non-coding RNAs (ncRNAs) has been recently identified in the genome of numerous cancers. Long ncRNAs (lncRNAs) belong to a new class of ncRNAs including tens of thousands different species. A fraction of these molecules shows a striking cancer-enriched expression pattern, suggesting an essential role in tumor cells and, possibly, a utility in therapeutic terms. This review aims at summarizing current knowledge for the identification and validation of lncRNAs as therapeutics targets in tumors. Both in-silico and wet-biology resources are presented in relation to the many challenges that the scientific community still needs to address in terms of lncRNA identification, stratification, patient personalization, drug delivery and toxicity.